1. Field of the Invention
The present invention relates to the field of hardware tool bits, and more particularly, the present invention relates to a device for removing damaged fasteners still embedded or otherwise engaged with a workpiece.
2. Description of the Prior Art
The use of fasteners, such as screws, bolts, and other threaded joining devices continues to increase. However, the more a fastener is used, the more likely that it becomes rounded off, broken, or otherwise rendered useless. At that point, the fasteners must be removed, and/or the workpiece replaced or abandoned.
A myriad of screw removing bits exist. Generally, the bits are typical in that each bit has a first end and a second end. The first end is adapted to be received by a rotating chuck or a rotating tool shaft, such as the shaft of a screw driver, either manually or power-driven. The second end of the bit is configured to impart rotational torque to the fastener while the later is still held fast by the workpiece.
The second end of the bit mimics the end of a standard drill bit. Several broken bolt extractors feature a left-handed cutting edge. For example, U.S. Pat. No. 4,777,850 discloses two such edges. However, such devices still require considerable power to impart the rotational torque necessary to “bite” into the fastener to begin left-handed extraction.
U.S. Pat. No. 6,595,730 B2 awarded to Bergamo on Jul. 22, 2003 discloses a bit for removing damaged screws. This device is designed to engage the exterior surface of the fasteners and not interior surfaces of the fastener. As such, “purchase” of the fastener by the device is relegated to that exterior surface.
A need exists in the art for a broken bolt or broken screw extraction device to facilitate easier removal of fasteners held tight by a workpiece. The device should be able to be utilized in hand-actuated handles or electrically activated tools. The device should engage as much of the interior surface of a wayward fastener so as to decrease the likelihood of a spin off of the device from the fastener while concomitantly increasing the likelihood of extraction of the fastener with minimal force required.